1. Field of the Invention
The present invention relates to a communication device, and communication method.
2. Description of the Related Art
In recent years, a great number of electronic devices have come to have wireless communication functions. Subsequently, in accordance therewith, various wireless communication standards have been established. Representative examples of personalized wireless techniques include a wireless LAN (hereafter, WLAN), and Bluetooth (registered trademark) (hereafter, BT). These wireless techniques are implemented in various devices, primarily multi-functional electric appliances such as personal computers (hereafter, PC), cell phones, electronic notebooks (hereafter, PDA), and so forth. Nowadays, with small embedded devices such as digital cameras, printers, and so forth as well, such a wireless technique has been employed. Hereafter, a device in which a wireless technique has been implemented will be referred to as a wireless device.
These wireless devices have come into widespread use and employed in many ways, thereby improving convenience for users. On the other hand, damage caused by wireless devices being invaded through networks, damage caused by personal information such as credit card information, passwords, and so forth, leaking and so forth, have been reported. Such damage has been recognized as social problems, and accordingly, enhancement of security with wireless devices has been strongly demanded.
In a case of BT, an authentication technique employing the maximum 16-byte key information (passkey) has been employed, and further, an encryption technique for transmission path has been included in a security function. However, in reality, a passkey of around four characters has been employed in many cases. With such an operation method, there are few combinations of passwords, which is at high risk of unjust authentication being performed. On the other hand, in a case of WLAN, an encryption system called as WEP has been implemented at first. However, it has been declared that this encryption system can be decrypted over a relatively short amount of time, following which robust encryption techniques such as WEP-TKIP system, WPA, WPA2, and so forth have been included in the standards.
A great number of methods have been provided regarding security functions. On the other hand, it has been a great burden for common users having no specialized knowledge regarding such techniques to perform appropriate settings according to the selected method. In many cases, the users consult with a manufacturer's technical support counter, or give up settings of a wireless device itself. As a result thereof, wireless devices with security not functioning sufficiently are employed, leading to an environment wherein wireless devices have not readily spread to home electric appliances.
Diligent research and development of a technique relating to enhancement of security, and a technique for simplifying network settings have been performed in light of the above-mentioned present situations. With regard to such a technique, for example, a technique relating to a setup method for WLAN has been disclosed in Japanese Unexamined Patent Application Publication No. 2004-215232. This document has disclosed a technique for narrowing down a communication range between an access point and a WLAN terminal by weakening radio field strength to narrow down a radio wave access range, thereby improving security. Further, this document has disclosed a connection unit which can complete setup of a network by buttons provided on the access point and the WLAN terminal being pressed simultaneously. Also, with regard to BT, Japanese Patent No. 3928489 has disclosed a technique relating to a method for completing connection settings simply by buttons provided on both connected devices being pressed. Such a technique is employed, thereby realizing network settings having high security by simple operations.